Expose UI to parents to "sign" the COPPA compliance

Since this module was originally developed with an external loading mechanism for parent/student relationships, COPPA compliance signing, and dob its a little rough around some edges.

Right now the COPPA "signing" page for parents is not exposed anywhere. This can currently be accessed via 'coppa/sign' for any parents with children.

This should be exposed in the user navigation block, the user profile or both.

If anybody has suggestions or comments for implementation; feel free to chime in.